1. Field of the Invention
The present invention relates to magnetic resonance imaging techniques.
2. Description of the Prior Art
Magnetic resonance imaging (MRI) is a powerful technology that provides clinical images with improved resolution and superior diagnostic value over computed tomography, particularly when applied to brain. Magnetic resonance images are created by processing and displaying digital information in the form of two dimensional or three dimensional displays, which are then subjectively, semi-objectively, or objectively interpreted by observers. The MR technology that produces images also creates quantitative MR data (including proton density, spin-lattice relaxation (T1), spin-spin relaxation (T2), and other factors that influence MR relaxation) that provide important information concerning the physical state of water in normal and pathologic tissues. However, certain diseases and conditions, especially reversible encephalopathies, low grade brain disease, drug effects, or diffuse brain disease may be very difficult or impossible to diagnose or detect using conventional MR techniques. Currently, these brain states can be detected by 1) cerebrospinal fluid analysis, 2) single photo emission tomography (SPECT), positron emission tomography (PET), electroencephalography (EEG), or magnetoencephalography (MEG). Although present in all conventional MRI sequences, quantitative digital data are usually lost or only poorly exploited during the process of image creation and in the subsequent interpretation by the radiologist or other clinical observer.
It is therefore an object of the present invention to provide MRI techniques that exploit the quantitative nature of magnetic resonance (MR) data, combined with image processing techniques, to determine quantitative digital data in pure brain tissues.
It is another object of the present invention to use quantitative digital data obtained in pure brain tissues to determine the properties of brain tissues, and especially gray matter which is exquisitely sensitive to and more diagnostic of active brain disease relative to white matter or lesional tissues.
It is yet another object of the present invention to provide MR techniques that provide powerful diagnostic information in a wide variety of disease states and provide a MR method for measuring active brain disease previously detectable by CSF analysis, SPECT, PET, EEG or MEG.
It is yet another object of the present invention to provide an MRI technique that broadly expands the power of MRI for the diagnosis and management of disease, yet does not necessarily require high MRI field strengths (greater than 1.5 Tesla) or strong field gradients (as is required in echo planar MR), and thus can be performed on a both simple, inexpensive low field units as well as expensive high-field, high-gradient units. Thus, this technique should make powerful MRI diagnosis more available even to centers with limited resources.
According to a first broad aspect of the present invention, there is provided a method for determining whether an individual has a central nervous system disease or injury comprising: obtaining a T2 measurement for at least one brain tissue sample from an individual; determining if the T2 measurement indicates the presence of a central nervous system disease or injury in the individual.
According to a second broad aspect of the invention, there is provided a method for determining whether an individual has a central nervous system disease or injury comprising: obtaining a first T2 measurement using an MRI technique for a brain tissue sample from an individual at a first time; obtaining a second T2 measurement using an MRI technique for the brain tissue sample from the individual at a second time; and comparing the second T2 measurement to the first T2 measurement.
According to a third broad aspect of the invention, there is provided a method for determining the effectiveness of a treatment for a central nervous system disease or injury comprising: obtaining a first T2 measurement using an MRI technique for a brain tissue sample from an individual at a first time; administering a first treatment to an individual; obtaining a second T2 measurement using the MRI technique for the brain tissue sample from the individual after administering the first treatment; and comparing the second T2 measurement to the first T2 measurement.
Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.